State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
Molecules. 2022 Oct 29;27(21):7371. doi: 10.3390/molecules27217371.
To reveal the nature of CO reduction to formate with high efficiency by in situ hydrogen produced from hydrothermal reactions with iron, DFT calculations were used. A reaction pathway was proposed in which the formate was produced through the key intermediate species, namely iron hydride, produced in situ in the process of hydrogen gas production. In the in situ hydrogenation of CO, the charge of H in the iron hydride was -0.135, and the Fe-H bond distance was approximately 1.537 Å. A C-H bond was formed as a transition state during the attack of H on C. Finally, a HCOO species was formed. The distance of the C-H bond was 1.107 Å. The calculated free energy barrier was 16.43 kcal/mol. This study may provide new insight into CO reduction to formate in hydrothermal reactions with metal.
为了揭示铁在水热反应中产生的原位氢气高效将 CO 还原为甲酸盐的本质，我们使用了密度泛函理论（DFT）计算。提出了一条反应途径，其中甲酸盐是通过原位生成的关键中间体物种，即铁氢化物，在氢气生成过程中生成。在 CO 的原位加氢中，铁氢化物中 H 的电荷为-0.135，Fe-H 键的距离约为 1.537 Å。在 H 对 C 的攻击过程中形成了 C-H 键作为过渡态。最后，形成了 HCOO 物种。C-H 键的距离为 1.107 Å。计算得到的自由能势垒为 16.43 kcal/mol。这项研究可能为金属水热反应中 CO 还原为甲酸盐提供新的见解。
